usb: gadget: composite: conditionally dequeue setup requests

This is an adoption of Kernel commit a7c12eaf2 ("usb: gadget: composite:
conditionally dequeue os_desc and setup requests"). Basically we only
want to dequeue ep0 requests when they are actually queued. Drivers like
dwc3 warn when unqueued requests are being tried to unqueued.

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

1 files changed, 40 insertions, 3 deletions

diff --git a/drivers/usb/gadget/composite.c b/drivers/usb/gadget/composite.c
index 1cfc49d1c5..b66aa6be97 100644
--- a/drivers/usb/gadget/composite.c
+++ b/drivers/usb/gadget/composite.c
@@ -1194,10 +1194,45 @@ EXPORT_SYMBOL_GPL(usb_string_ids_n);
 
 static void composite_setup_complete(struct usb_ep *ep, struct usb_request *req)
 {
+	struct usb_composite_dev *cdev;
+
 	if (req->status || req->actual != req->length)
 		DBG((struct usb_composite_dev *) ep->driver_data,
 				"setup complete --> %d, %d/%d\n",
 				req->status, req->actual, req->length);
+
+	/*
+	 * REVIST The same ep0 requests are shared with function drivers
+	 * so they don't have to maintain the same ->complete() stubs.
+	 *
+	 * Because of that, we need to check for the validity of ->context
+	 * here, even though we know we've set it to something useful.
+	 */
+	if (!req->context)
+		return;
+
+	cdev = req->context;
+
+	if (cdev->req == req)
+		cdev->setup_pending = false;
+	else
+		WARN(1, "unknown request %p\n", req);
+}
+
+static int composite_ep0_queue(struct usb_composite_dev *cdev,
+		struct usb_request *req)
+{
+	int ret;
+
+	ret = usb_ep_queue(cdev->gadget->ep0, req);
+	if (ret == 0) {
+		if (cdev->req == req)
+			cdev->setup_pending = true;
+		else
+			WARN(1, "unknown request %p\n", req);
+	}
+
+	return ret;
 }
 
 /*
@@ -1226,6 +1261,7 @@ composite_setup(struct usb_gadget *gadget, const struct usb_ctrlrequest *ctrl)
 	 * when we delegate to it.
 	 */
 	req->zero = 0;
+	req->context = cdev;
 	req->complete = composite_setup_complete;
 	req->length = 0;
 	gadget->ep0->driver_data = cdev;
@@ -1469,7 +1505,7 @@ unknown:
 	if (value >= 0 && value != USB_GADGET_DELAYED_STATUS) {
 		req->length = value;
 		req->zero = value < w_length;
-		value = usb_ep_queue(gadget->ep0, req);
+		value = composite_ep0_queue(cdev, req);
 		if (value < 0) {
 			DBG(cdev, "ep_queue --> %d\n", value);
 			req->status = 0;
@@ -1621,7 +1657,8 @@ void composite_dev_cleanup(struct usb_composite_dev *cdev)
 		kfree(uc);
 	}
 	if (cdev->req) {
-		usb_ep_dequeue(cdev->gadget->ep0, cdev->req);
+		if (cdev->setup_pending)
+			usb_ep_dequeue(cdev->gadget->ep0, cdev->req);
 		kfree(cdev->req->buf);
 		usb_ep_free_request(cdev->gadget->ep0, cdev->req);
 	}
@@ -1753,7 +1790,7 @@ void usb_composite_setup_continue(struct usb_composite_dev *cdev)
 	} else if (--cdev->delayed_status == 0) {
 		DBG(cdev, "%s: Completing delayed status\n", __func__);
 		req->length = 0;
-		value = usb_ep_queue(cdev->gadget->ep0, req);
+		value = composite_ep0_queue(cdev, req);
 		if (value < 0) {
 			DBG(cdev, "ep_queue --> %d\n", value);
 			req->status = 0;